Suppose that I want to end a turn at a precise distance from a planet or warplanet. If i enter the co-ordinates to full points, the closest i might obtain to the required distance is, for example, 0.2 light years further (or less) than desired.

If i enter co-ordinates by hand, in the URL, can i enter one or both of them as a decimal place? Will that have any effect, or does the system round off anyway? If you can, how many decimal places?

true.
if you found someones hp, and it is undefended (if tat is the case they deserve to be taken 8D ), then they will not see you coming, and have no chance.....with one day, they can move some ships on neighbouring systems, or change their hp..........

-The bold text with "xxxxx" and "yyyyy" is where the coordinate locations are.
-After some testing, I found that "aaaaa" is what you are flying towards. If "aaaaa"=0, you are flying towards empty space. "aaaaa"=1 is a planet, and "aaaaa"=2" is a warplanet.
-"bbbbb" is the ID of a planet or warplanet. If you are flying towards empty space, then "bbbbb"=0. "bbbbb" is a 5-digit number for planets and a 4-digit number for warplanets.
-"Weg_act" has not been tested yet, but I am assuming it sets your waypoint.

So you copy the URL above and type in the xpos and ypos for your destination, and that's it.